Chemists at the University of Surrey found that people infected with the virus appear to have lower lipid levels in the natural oils that coat the surface of their skin.
The most widely used approach to detecting Covid-19 requires a polymerase chain reaction (PCR) test, which involves taking a swab of the back of the throat and far inside the nose.
This type of invasive testing can return incorrect results if not carried out properly, leading to false negatives in some cases.
Scientists hope non-invasive skin swab samples could be used to offer a quick and easy alternative to the PCR tests.
As part of the Surrey study, which was conducted alongside Frimley NHS Trust and the universities of Manchester and Leicester, researchers collect sebum samples from 67 hospitalised patients – 30 who had tested positive for Covid-19 and 37 who had tested negative.
Sebum is an oily, waxy substance produced by microscopic glands in the skin and is particularly abundant on the face, neck or back.
The researchers then analysed the molecular make-up of the swabs and used statistical modelling to differentiate between the different samples.
It was found that patients with a positive Covid-19 test had lower lipid levels on the surface of their skin than their counterparts with a negative test.
This form of testing was 57 per cent accurate in correctly separating between positive and negative Covid samples, which increased to 79 per cent when medication used by the patients and additional health conditions were taken into account.
Covid-19 is known to disrupt the functioning of the body’s metabolic mechanisms, and the Surrey scientists said their findings suggested the ability of the virus to impact the body’s internal regulatory processes extended to the production and maintenance of lipid levels in the skin.
“Given that samples can be provided quickly and painlessly, we conclude that sebum is worthy of future consideration for clinical sampling,” the researchers added.
Dr Melanie Bailey, co-author of the study from the University of Surrey, said: “Our study suggests that we may be able to use non-invasive means to test for diseases such as Covid-19 in the future – a development which I am sure will be welcomed by all.”
Matt Spick, who also co-authored the study, said: “Covid-19 damages many areas of metabolism. In this work, we show that the skin lipidome can be added to the list, which could have implications for the skin’s barrier function, as well as being a detectable symptom of the disease itself.”